The present invention relates to the mounting of a magnetic recording head in relation to a flexible recording medium, such as a magnetic disk; and more particularly, the invention relates to head loading in flexible disk systems in which two heads are either caused to engage the disk from opposite sides or are retracted therefrom.
It is generally known to mount such heads on resilient carriers which are flexed back and restrained in the head retracting position, while release of the restraint causes the resiliency of the carriers to urge the heads towards each other and in engagement with a flexible medium in between. The heads are urged into this engaging position by the resiliency of the carrier and at a particular force. The amount of force so exerted upon the disk must be very small, such as 7 grams.
A conventional head mounting structure is constructed for the purpose above uses two non-resilient members which are pivotably connected to stationary frame parts, each carrying spring means for mounting the heads. Upon pivoting the members towards each other, the heads engage the media as described. The springs carrying the heads are normally relaxed but are flexed on contact with the medium and, through the medium, flex each other. The known springs for this purpose are constructed in that a center leaf spring extends from a mounting piece, and a thin mounting platform for the head is disposed in front of the center leaf spring and held by thin arms extending from the mounting piece along both sides of the center spring. The latter is additionally provided with arms or extensions extending above and below the platform. The arm below engages the platform when the non-resilient mounting members are pivoted towards each other to exert a definite force upon the head carrying platform and in the head loading position. The arms above the platform extend alongside the head and engage the platform when the center spring is permitted to relax, carrying the platform back as the non-resilient mounting members are pivoted back.
While the spring construction as outlined in the previous paragraph is of a quite advantageous design, its mounting and actuation is actually insufficient to establish the desired accuracy of the force being exerted. It was found, particularly, that the mounting of these springs on pivotable members by means of mounting pieces permits only inadequate control of the spring actuation and head loading force.